Hypotension in the low birth weight (LBW) and extremely low birth weight (ELBW) infant is often encountered in the postnatal adaptation phase. Severe, prolonged hypotension contributes to cellular dysfunction and cell death. Systemic hypotension affects close to half of all ELBW infants and a significant portion of LBW infants. The true definition of hypotension remains to be a question. There is a linear association between birth weight, gestational age, and mean blood pressure but blood pressure can vary significantly in the first day of life. The critical period tends to be the first 24-36 hours of life as blood pressure tends to rise significantly in the first 72 hours of life regardless of gestational age. Preterm infants suffering from hypotension have a higher incidence and increased severity of intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and long-term neurodevelopmental sequelae compared to normotensive preterm infants. Effects on other organ systems can result in renal injury, hepatic injury, and the development of necrotizing enterocolitis among other complications. An important aspect in the management of infants with hypotension is the decision of when to treat and with what agent. Dopamine is commonly used as first-line therapy, but issues with efficacy and its side effect profile have lessened its favorability over the years. Few studies compare dopamine to other agents as a first -line treatment. This study hopes to contribute to the literature information on vasopressin as a potential first-line agent for treatment of neonatal hypotension in low birth weight infants.